Gas Quality and LNG Research Study
Appendix B - 2
LNG Research Study
Commercial Water Boiler
September 2004
Prepared By:
The Southern California Gas Company
Engineering Analysis Center – Applied Technologies
Jorge Gutierrez
Firas Hamze
Juan R. Mora
Andre Saldivar
Gas Quality and LNG Research Study
Appendix B - 2
Acknowledgements
The authors express appreciation to the following associates whose efforts contributed
much to the success of this project.
Monica Clemens
Alfonso Duarte
David Kalohi
Johnny Lozano
William F. Raleigh
Larry Sasadeusz
Rod Schwedler
Kevin Shea
Dale Tomlinson
Disclaimer
LEGAL NOTICE
ƒ The Southern California Gas Company, its officers, employees, and contractors,
make no warranty, expressed or implied, and assume no legal liability for
accuracy of the information contained in this report; neither do they individually or
collectively assume any liability with respect to the use of such information or
report or for any damages which may result from the use of or reliance on any
information, apparatus, methods, or process disclosed or described in or by this
report.
ƒ No information contained in this report can be copied, reported, quoted, or cited
in any way in publications, papers, brochures, advertising, or other publicly
available documents without the prior written permission of the Southern
California Gas Company.
Commercial Water Boiler
i
Gas Quality and LNG Research Study
Appendix B - 2
Table of Contents
Results Summary.............................................................................................................. 2
Rated Input Test ............................................................................................................ 2
At Various Input Rates Using Baseline Gas Test .......................................................... 3
Equipment Selection Criteria............................................................................................. 4
Equipment Specifications.................................................................................................. 4
Standards.......................................................................................................................... 4
Installation ......................................................................................................................... 5
Test Gases........................................................................................................................ 5
Test Procedure.................................................................................................................. 6
Rated Input Test ............................................................................................................ 6
At Various Input Rates Using Baseline Gas Test .......................................................... 7
Cold Ignition Test........................................................................................................... 7
Hot Ignition Test............................................................................................................. 7
Results ............................................................................................................................. 8
Rated Input Test ............................................................................................................ 8
Input............................................................................................................................ 8
Temperatures ............................................................................................................. 9
Emissions ................................................................................................................. 10
At Various Input Rates Using Baseline Gas Test ........................................................ 11
Input..........................................................................................................................11
Temperature ............................................................................................................. 12
Emissions ................................................................................................................. 13
Cold Ignition Test......................................................................................................... 14
Hot Ignition Test........................................................................................................... 14
Appendix A: Protocol....................................................................................................... 15
Appendix B: Table of Averages....................................................................................... 22
Appendix C: Test Gases ................................................................................................. 24
Appendix D: Zero, Span and Linearity Tables ................................................................ 25
Appendix E: Calculations ................................................................................................ 27
Appendix F: Test Equipment........................................................................................... 31
Appendix G: Test Set-Up/Schematic .............................................................................. 32
Commercial Water Boiler
1
Gas Quality and LNG Research Study
Appendix B - 2
Results Summary
Results obtained from all tests reveal (a) there were no operational, ignition, flame
stability, or safety problems; (b) CO emissions were below 14 ppm; (c) Flame
temperature, flame length, partial orange tinting of the flame, NOX, and equivalence ratio
followed the same pattern as the Wobbe Number; (d) CO and HC followed the opposite
pattern as the Wobbe Number. After manufacturer reviewed the data they expresed
concerns with the higher emissions, higher temperatures, and longer flames observed
with richer gases.
Rated Input Test
Average NOX emissions values were below 44 ppm (corrected to 3% O2), average CO
emissions values were below 15 ppm (corrected to 3% O2) and average flame
temperatures ranged between 1,100°F and 2,000°F for all gases tested.
Commercial Water Boiler
Summary Chart
Rated Input Test
August 19, 2004
Gas 6
Base
Gas 5A
Gas 5
Base
Gas 4A
Gas 4
Base
Gas 3
Base
Base
2,400
Gas 2
96
Base
2,000
φ
Equivalent Ratio X 100 (φ)
NOX & CO (ppm @ 3% O2)
64
1,600
Flame
Wobbe
48
32
1,200
Heating
Value
800
NOX
16
400
CO
0
12:30 PM
12:45 PM
1:00 PM
1:15 PM
1:30 PM
1:45 PM
2:00 PM
2:15 PM
2:30 PM
0
2:45 PM
Time
NOTE: Emission test results are for information purposes. They were not the result of certified tests.
Commercial Water Boiler
2
Heating Value & Wobbe Number (Btu/cf)
Flame Temperature (°F)
80
Gas Quality and LNG Research Study
Appendix B - 2
At Various Input Rates Using Baseline Gas Test
Results show there were no problems with the boiler set to rated input, 6% under fired or
6% over fired conditions while utilizing Baseline Gas.
Commercial Water Boiler
Summary Chart
At Various Input Rates Using Baseline Gas
August 20, 2004
2,400
Base
(Adjustment)
6%
Under Fired
Base
(Adjustment)
6%
Over Fired
80
Rated Input
2,000
φ
Equivalent Ratio X 100 (φ)
NOX & CO (ppm @ 3% O2)
64
1,600
Flame
Wobbe
48
1,200
Heating Value
32
800
NOX
16
400
CO
0
10:00 AM
10:10 AM
10:20 AM
10:30 AM
10:40 AM
10:50 AM
0
11:00 AM
Time
NOTE: Emission test results are for information purposes. They were not the result of certified tests.
Commercial Water Boiler
3
Heating Value & Wobbe Number (Btu/cf)
Flame Temperature (°F)
Rated Input
Base
(Adjustment)
96
Gas Quality and LNG Research Study
Appendix B - 2
Equipment Selection Criteria
This unit was selected because it is used extensively in our service territory and it uses a
ceramic power burner adjusted to operate at a very high firing intensity rate for a surface
burner (6,369 Btu/hr-in2). This could create the following issues when high-energy
content gases are utilized: 1) This type of burner generates a long flame that, if it
becomes too long, could be quenched by the heat exchanger and generate high CO or
damage the heat exchanger and 2) CO, HC and NOX emissions can easily increase
since air for combustion is fixed.
In addition, this unit was selected because it has to meet very stringent regulations.
Rule 1146.2 from the SCAQMD limits NOX to 30 ppm (corrected to 3% O2) and CO to
400 ppm (corrected to 3% O2). The ANSI Z21.10.3 and UL standards cover safety,
construction, performance and limit CO emissions to 400 ppm (corrected to 0% O2).
Equipment Specifications
ƒ
ƒ
ƒ
ƒ
ƒ
ƒ
Description: Space heating commercial water boiler with tube type heat
exchanger
Burner: Gas fired premix surface burner operating on a blue flame mode
Maximum input rating: ~500,000 Btu/hr
Minimum input rating: ~250,000 Btu/hr
Type of fuel: Natural Gas
Required gas supply pressure: 5” w.c. - 14” w.c.
Standards
A detailed description of the protocol and some of the rationale used to develop the test
procedures are included in Appendix A The test protocol was developed based on the
following test standards.
ƒ ANSI Z21.13-2000, Standard for Gas-Fired Low-Pressure Steam and Hot Water
Boilers.
ƒ South Coast Air Quality Management District Rule 1146.2, Emission of NOX from
Large Water Heaters and Small Boilers, adopted January 9, 1998.
ƒ South Coast Air Quality Management District Protocol, NOX Compliance Testing
for Natural Gas-fired Water Heaters and Small Boilers, last amended January
1998.
ƒ South Coast Air Quality Management District – Instrumental analyzer procedure
for continuous gaseous emissions - District Method 100.1.
Commercial Water Boiler
4
Gas Quality and LNG Research Study
Appendix B - 2
Installation
The manufacturer installed the boiler according to their specifications for outdoor
installation. The boiler inlet water temperature and pressure were set and maintained at
125 ± 5°F and 25 ± 1 psig to ensure steady state boiler operation and prevent it from
cycling while performing the test sequence.
Instrumentation was installed following the above test standards and input from
manufacturers and consultants. Thermocouples were installed to measure flame, makeup water, inlet & outlet hot water, flue gas, ambient and gas temperatures. Also,
pressure transducers were installed to measure manifold, skid, and inlet water supply
pressures. A gas meter was set to measure the gas flow.
A straight vertical vent pipe, five feet in length and of the diameter of the boiler vent
collar, was provided. An integrated sampling probe, constructed per the AQMD protocol,
ten inches from the bottom of the vent pipe was installed and a three-point thermocouple
grid (wired as a thermopile) was placed six inches from the bottom of the vent pipe.
Once all testing instruments were installed, the boiler was run on the facilities pipeline
gas to verify that the boiler and all instrumentation operated properly. Manifold and
supply pressures were not adjusted during set-up.
Test Gases
The following gases have been specifically formulated to cover the range of gas
compositions and calorific values of natural gases that could be delivered in the
Southern California Gas Company territory by current natural gas suppliers and future
LNG suppliers. Composition details are specified in Appendix C.
ƒ Baseline Gas (Gas 1) - Low Wobbe (1,302 Btu/cf), low heat content gas (1,001
Btu/cf)
ƒ Gas 2 - Lowest-Wobbe (1,269 Btu/cf), lowest-heat content gas (974 Btu/cf)
ƒ Gas 3 - Highest-Wobbe (1,436 Btu/cf), highest-heat content gas (1,152 Btu/cf)
ƒ Gas 4 - Medium-Wobbe (1,370 Btu/cf), highest-heat content gas (1,145 Btu/cf)
ƒ Gas 4A (4 component mix) - Medium-Wobbe (1,371 Btu/cf), highest-heat content
gas (1,148 Btu/cf)
ƒ Gas 5 - Medium-Wobbe (1,373 Btu/cf), high-heat content gas (1,099 Btu/cf)
ƒ Gas 5A (4 component mix) - Medium-Wobbe (1,374 Btu/cf), high-heat content
gas (1,100 Btu/cf)
ƒ Gas 6 - High Wobbe (1.412 Btu/cf), high-heat content gas (1,107 Btu/cf)
Commercial Water Boiler
5
Gas Quality and LNG Research Study
Appendix B - 2
Test Procedure
Tests procedures were developed following the above test standards. When the test
standards were difficult to meet due to limited resources and time restrictions, input from
manufacturers and consultants was requested to determine simplified test alternatives.
Before every test, the following steps were performed:
ƒ All emissions analyzers were calibrated and checked for linearity.
ƒ Data logger was enabled and temperatures, pressures, and gas flow readings
were verified.
During every test, the following steps were performed:
ƒ Baseline and Substitute Gases were run continuously with manual switching
between gases taking less than 30 seconds.
ƒ Emissions, pressure and temperature data was observed before, during and after
changeover.
After every test, the following steps were performed:
ƒ Test data was downloaded.
ƒ Linearity and drift inspections were performed on all emissions analyzers.
Rated Input Test
Using Baseline Gas, the manifold pressure was adjusted to achieve a rated input of
500,000 Btu/hr ± 2%. Once readings were stable, data collection was started and the
gases were run continuously in the following order.
ƒ Baseline Gas for 10 minutes
ƒ Gas 2 for 10 minutes
ƒ Reestablish Baseline Gas for 5 minutes
ƒ Gas 3 for 10 minutes
ƒ Reestablish Baseline Gas for 5 minutes
ƒ Gas 4 for 3 minutes
ƒ Gas 4A for 10 minutes
ƒ Reestablish Baseline Gas for 5 minutes
ƒ Gas 5 for 10 minutes
ƒ Gas 5A for 10 minutes
ƒ Reestablish Baseline Gas for 5 minutes
ƒ Gas 6 for 10 minutes
ƒ Conclude testing with Baseline Gas for 5 minutes
Commercial Water Boiler
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Gas Quality and LNG Research Study
Appendix B - 2
At Various Input Rates Using Baseline Gas Test
The manifold pressure was adjusted to achieve a rated input of 500,000 Btu/hr ± 2% to
begin the test. Once this condition was met, the boiler was operated with Baseline Gas
was run continuously in the following manner:
ƒ At Rated Input for 10 minutes
ƒ 6% Under Fire Adjustment (8 minutes)
ƒ At 470,000 Btu/hr ± 2% (6% Under Fire) 10 minutes
ƒ 6% Over Fire Adjustment (7 minutes)
ƒ At 530,000 Btu/hr ± 2% (6% Over Fire) 10 minutes
ƒ Rated Input Adjustment (3 minutes)
ƒ At Rated Input for 10 minutes to conclude testing
Cold Ignition Test
Using Baseline Gas, manifold pressure was adjusted to achieve a rated input of 500,000
Btu/hr ± 2%. The following steps were followed:
ƒ The gas delivery system was purged with Gas 3 (Highest-Wobbe Number).
ƒ The commercial water boiler was ignited (using Gas 3) from a cold start and data
was collected for one minute. For each time the boiler was ignited, visual
observations of the flame and ignition delays were documented. This test was
repeated 2 more times, allowing the boiler to reestablish cold start conditions in
between each ignition.
ƒ The gas delivery system was purged with Gas 2 (Lowest-Wobbe Number).
ƒ The commercial water boiler was ignited (using Gas 2) from a cold start and data
was collected for one minute. For each time the boiler was ignited, visual
observations of the flame and ignition delays were documented. This test was
repeated 2 more times, allowing the boiler to reestablish cold start conditions in
between each ignition.
Hot Ignition Test
Using Baseline Gas, manifold pressure was adjusted to achieve a rated input of 500,000
Btu/hr ± 2%. The following steps were followed:
ƒ The gas delivery system was purged with Gas 3 (Highest-Wobbe Number).
ƒ The commercial water boiler was ignited (using Gas 3) and data was collected
for one minute. For each time the boiler was ignited, visual observations of the
flame and ignition delays were documented. This test was repeated 2 more times
with no more than one minute elapsing between tests.
ƒ The gas delivery system was purged with Gas 2 (Lowest-Wobbe Number).
ƒ The commercial water boiler was ignited (using Gas 2) and data was collected
for one minute. For each time the boiler was ignited, visual observations of the
flame and ignition delays were documented. This test was repeated 2 more times
with no more than one minute elapsing between tests.
Commercial Water Boiler
7
Gas Quality and LNG Research Study
Appendix B - 2
Results1, 2
Rated Input Test
Input
During the 1st Baseline Gas run, the commercial water boiler operated at approximately
478,000 Btu/hr; 4.4% below rated input. Both manifold and supply pressures remained
within the limits set by the test protocol despite slight fluctuations in supply pressure.
The gas flow rate varied due to different gas compositions and the presence of heavier
components in some of the gases tested. Baseline Gas achieved the highest flow rate
(478 scfh - 1st run) and Gas 4A experienced the lowest flow rate (446 scfh) among all
gases tested. The highest input rate was experienced with Gas 3 (526,659 Btu/hr),
while the lowest input rate occurred with Gas 2 (464,211 Btu/hr).
Commercial Water Boiler
Input Chart
Rated Input Test
August 19, 2004
Base
Supply & Manifold Pressure (in. w.c.)
10
1,550
Supply
8
1,300
Heating
Value
Wobbe
6
1,050
Manifold
4
800
2
550
SCFH
0
12:30 PM
SCFH, Heating Value (Btu/cf), Wobbe Number (Btu/cf)
& Input Rate/1000 (Btu/hr)
Gas 6
Base
Gas 5A
Gas 5
Base
Gas 4A
Gas 4
Base
Base
Base
Gas 3
1,800
Gas 2
12
Input
Rate
12:45 PM
1:00 PM
1:15 PM
1:30 PM
1:45 PM
2:00 PM
2:15 PM
2:30 PM
300
2:45 PM
Time
1
2
All emissions, temperature and input values mentioned throughout the results section are average values.
CO, HC & NOX emissions data are corrected to 3% O2.
Commercial Water Boiler
8
Gas Quality and LNG Research Study
Appendix B - 2
Temperatures
The highest flame temperature was reached with Gas 3 (1,996°F), followed by Gas 6
(1,986°F) and Gas 4A (1,941°F). Furthermore, Gas 2 (1,138°F) held the lowest flame
temperature. Although the flame temperature, as measured with a fixed thermocouple
tip, fluctuated when different test gases were introduced. Some of the temperature
fluctuations were due to the changes of flame height and shape with respect to the
thermocouple tip, which was not moved during the series of tests. The thermocouple tip
was installed, during the instrumentation set up, in the secondary cone of the flame
when the equipment was operating with Baseline Gas.
Stack temperature was highest with Gas 3 (508°F), followed by Gas 6 (503°F) and Gas
4A (502°F). Gas 2 held the lowest stack temperature at 485°F.
The inlet water and outlet water temperatures were highest with Gas 6 at temperatures
of 127°F and 161°F.Both ambient and gas temperatures remained stable at 78 ± 3°F for
the entire test period.
Commercial Water Boiler
Temperature, Pressure & Water Flow Chart
Rated Input Test
August 19, 2004
Gas 6
Base
Gas 5A
Gas 5
Base
Gas 4A
Gas 4
Base
Gas 3
Base
Gas 2
2,400
Base
240
Base
2,000
Flame
160
1,600
Outlet
Water
120
1,200
Inlet
Water
Temp
Ambient
80
800
Gas
Stack
40
0
12:30 PM
400
Inlet Water Press.
Water
Flow
12:45 PM
1:00 PM
1:15 PM
1:30 PM
1:45 PM
Time
Commercial Water Boiler
9
2:00 PM
2:15 PM
2:30 PM
0
2:45 PM
Stack & Flame Temperatures (°F)
Ambient, Gas, Inlet & Outlet Water Temperatures (°F)
Inlet Water Pressure (psig), Water Flow (gal/min)
200
Gas Quality and LNG Research Study
Appendix B - 2
Emissions
NOx emissions values were highest with Gas 3 (43 ppm) followed by Gas 6 (38 ppm).
NOX emissions values for Gases 2, 4, 4A, 5 and 5A did not exceed 31 ppm, with the
lowest observed NOX emissions value occuring with Gas 2 (12 ppm). Baseline Gas NOx
emissions ranged between 15 and 17 ppm.
CO emissions values did not exceed 15 ppm, with the highest and the lowest values
being observed with Gas 2 (15 ppm) and with Gas 5A (<0.5 ppm). Also, HC emissions
followed the same patterns as CO emissions throughout the test period.
The Gas 4 run was short because there was insufficient gas supply, thus, no
comparisons could be made with Gas 4A. The only noticeable differences between
results for Gas 5 and Gas 5A were slight decreases in NOX, flame temperature, and
input rate during the Gas 5A run.
Commercial Water Boiler
Emissions Chart
Rated Input Test
August 19, 2004
Gas 6
Base
Gas 5A
Gas 5
Base
Gas 4A
Gas 4
Base
Gas 3
Gas 2
Base
72
Base
12
Base
10
60
Raw O2 & Raw CO2 (%)
8
48
CO2
6
36
HC
4
24
NOX
2
12
CO
0
12:30 PM
12:45 PM
1:00 PM
1:15 PM
1:30 PM
1:45 PM
2:00 PM
2:15 PM
2:30 PM
0
2:45 PM
Time
NOTE: Emission test results are for information purposes. They were not the result of certified tests.
Commercial Water Boiler
10
CO, HC & NOX (ppm @ 3% O2)
O2
Gas Quality and LNG Research Study
Appendix B - 2
At Various Input Rates Using Baseline Gas Test
Input
The commercial water boiler operated at approximately 4.4% below rated input when the
manifold pressure was adjusted to manufacturer specifications. The boiler was adjusted
to operate at three conditions: Rated Input (500,000 Btu/hr ± 2%), 6% Under Fired
(470,000 Btu/hr ± 2%) and 6% Over Fired (530,000 Btu/hr ± 2%). At each of the three
conditions, the boiler did not stay within the ± 2% range required for each firing rate.
The gas flow was highest during the 6% over fired run with a flow of 510 scfh. Supply
and manifold pressure varied throughout all runs due to regulator adjustments on the
appliance to achieve the appropriate input rate.
Commercial Water Boiler
Input Chart
At Various Input Rates Using Baseline Gas
August 20, 2004
1,800
6%
Under Fired
Base
(Adjustment)
6%
Over Fired
Supply & Manifold Pressure (in. w.c.)
10
Rated Input
1,550
Supply
8
1,300
Wobbe
Heating Value
6
1,050
Manifold
4
800
2
550
Input Rate
SCFH
0
10:00 AM
10:10 AM
10:20 AM
10:30 AM
Time
Commercial Water Boiler
11
10:40 AM
10:50 AM
300
11:00 AM
SCFH, Heating Value (Btu/cf), Wobbe Number (Btu/cf)
& Input Rate/1000 (Btu/hr)
Base
(Adjustment)
Rated Input
Base
(Adjustment)
12
Gas Quality and LNG Research Study
Appendix B - 2
Temperature
The highest flame temperature occurred when the commercial water boiler was overfired by 6% with a value of 1,966°F. The lowest flame temperature occurred when the
boiler was under-fired by 6% with a value of 1,080°F. The first run at rated input
reached a flame temperature of 1,473°F, increasing during the last rated input run to
1,704°F. Although the flame temperature, as measured with a fixed thermocouple tip,
fluctuated when different test gases were introduced. Some of the temperature
fluctuations were due to the changes of flame height and shape with respect to the
thermocouple tip, which was not moved during the series of tests. The thermocouple tip
was installed, during the instrumentation set up, in the secondary cone of the flame
when the equipment was operating with Baseline Gas.
Stack temperature was highest when the boiler was over fired by 6% with a value of
506°F and lowest during the 6% under-fire run with a value of 480°F. At rated input, a
stack temperature of 493°F was observed for the 1st run, but increased to 502°F for the
last run at rated input.
The outlet water temperature was highest when the boiler was over fired by 6% at a
temperature of 167°F. The inlet water temperature was highest for the last rated input
run with a temperature of 131°F, followed by the 6% over-fired run with a temperature of
130°F.
Commercial Water Boiler
Temperature, Pressure & Water Flow Chart
At Various Input Rates Using Baseline Gas
August 20, 2004
2,400
Rated Input
Base
(Adjustment)
6%
Under Fired
Base
(Adjustment)
6%
Over Fired
Rated Input
2,000
Outlet Water
160
1,600
Inlet Water
Temp
Flame
120
1,200
Gas
80
800
Ambient
Stack
40
400
Inlet Water Press.
Water Flow
0
10:00 AM
10:10 AM
10:20 AM
10:30 AM
Time
Commercial Water Boiler
12
10:40 AM
10:50 AM
0
11:00 AM
Stack & Flame Temperatures (°F)
Ambient, Gas, Inlet & Outlet Water Temperatures (°F)
Inlet Water Pressure (psig), Water Flow (gal/min)
200
Base
(Adjustment)
240
Gas Quality and LNG Research Study
Appendix B - 2
Emissions
The highest NOX emissions value was observed when the boiler operated at 6% overfired conditions, achieving a value of 25 ppm. The NOX emissions value during the 6%
under-fired run was lowest with a value of 9 ppm. During the first run at rated input, the
NOX value was 12 ppm and increased to 15 ppm for the last run.
The highest CO emissions value was observed during 6% under-fired conditions with a
value of 13 ppm. At 6% over-fired conditions, the lowest CO value was achieved (<1
ppm). During the first run at rated input, the CO emissions value was 3 ppm and
decreased to less than 1 ppm for the last run. Also, HC emissions followed the same
patterns as CO emissions.
Commercial Water Boiler
Emissions Chart
At Various Input Rates Using Baseline Gas
August 20, 2004
72
Rated Input
Base
(Adjustment)
6%
Under Fired
Base
(Adjustment)
6%
Over Fired
10
Base
(Adjustment)
12
Rated Input
60
Raw O2 & Raw CO2 (%)
8
48
CO2
6
36
HC
4
24
NOX
2
12
CO
0
10:00 AM
10:10 AM
10:20 AM
10:30 AM
10:40 AM
10:50 AM
0
11:00 AM
Time
NOTE: Emission test results are for information purposes. They were not the result of certified tests.
Commercial Water Boiler
13
CO, HC & NOX (ppm @ 3% O2)
O2
Gas Quality and LNG Research Study
Appendix B - 2
Cold Ignition Test
Orange tipping is normally luminance associated to high temperatures and not related
with incomplete combustion.
Cold Ignition Test
Gas Ignition
Start-Up #
1
3
Normal
2
3
1
2
Normal
Comments & Observations
Some orange tipping, good blue flame
near burner surface
Flame covered the entire burner surface
Some orange tipping, good blue flame
near burner surface
Flame covered the entire burner surface
Some orange tipping, good blue flame
near burner surface
Flame covered the entire burner surface
Flame did cover entire burner surface,
some orange tipping was noticed
Flame flickered at burner surface
Flame did cover entire burner surface,
some orange tipping was noticed
2
Flame flickered at burner surface
Flame did cover entire burner surface,
Flame flickered at burner surface
3
Hot Ignition Test
Orange tipping is normally luminance associated to high temperatures and not related
with incomplete combustion.
Hot Ignition Test
Gas Ignition
Start-Up #
1
2
Normal
2
1
3
Normal
2
Commercial Water Boiler
Comments & Observations
Flame puffing was noticed
Flame did not cover the entire burner
surface
Flame puffing was noticed
Flame did not cover the entire burner
surface
No puffing was noticed; flame more
stable
Flame covered the entire burner surface
Longer flame size and orange colored
flame were noticed.
No puffing was noticed; flame more
stable
Flame covered the entire burner surface
Longer flame size and orange colored
flame were noticed
14
Gas Quality and LNG Research Study
Appendix B - 2
Appendix A: Protocol
1. Standards
ƒ ANSI Z21.13-2000, Standard for Gas-Fired Low-Pressure Steam and Hot Water
Boilers.
ƒ South Coast Air Quality Management District Rule 1146.2, Emission of NOX from
Large Water Heaters and Small Boilers, adopted January 9, 1998.
ƒ South Coast Air Quality Management District Protocol, NOX Compliance Testing
for Natural Gas-fired Water Heaters and Small Boilers, last amended January
1998.
2. Boiler Data
ƒ Description: Space heating commercial water boiler with tube type heat
exchanger
ƒ Burner: Gas fired premix surface burner operating on a blue flame mode
ƒ Maximum input rating: ~500,000 BTU/hr
ƒ Minimum input rating: ~250,000 BTU/hr
ƒ Type of fuel: Natural gas
ƒ Required gas supply pressure: 5” w.c. - 14” w.c.
3. Test Arrangement
3.1. Basic setup – The boiler is to be tested on a leveled concrete surface. Fuel
gas, electrical power, and water are to be provided at rates and conditions
required by the test standards and manufacturer specifications. Combustion
products are to be sampled in a vent stack constructed per emission
measurement standards.
3.2. Water flow and piping – Provide water at the flow rate and temperature
required by the test standards and manufacturer specifications. If necessary,
provide a supply water pump, a recirculation pump, and valves necessary to
adjust water flow rate and temperatures. Maintain water pressure at a level
sufficient to ensure proper boiler operation.
3.3. Vent pipe - For all testing, a straight vertical vent pipe, five feet in length and of
the diameter of the boiler vent collar, is to be provided. Provide an integrated
sampling probe, constructed per the AQMD protocol, ten inches from the bottom
of the vent pipe. Six inches from the bottom of the pipe, provide a three-point
thermocouple grid, wired as a thermopile.
3.4. Fuel gas - Fuel gases are to be provided at the pressures required by test
methods specified later in this protocol. Pressure is to be measured at the inlet
pressure tap of the boiler gas control.
3.5. Electrical power - Electrical power is to be provided at the voltage specified on
the boiler rating plate ± 1%.
Commercial Water Boiler
15
Gas Quality and LNG Research Study
Appendix B - 2
3.6. Temperatures - In addition to data required for firing rate, provide
thermocouples in inlet and outlet water piping as prescribed in Figure 8 of the
AQMD protocol, as close to the boiler as possible. Also provide a thermocouple
for measurement of the test ambient temperature – at mid-height of the boiler
and shielded from abnormal radiation and convective effects.
Provide thermocouples in other locations as appropriate to record possible
effects of gas blend changes. If possible seek assistance from the manufacturer
selecting locations.
3.7. Instrumentation – All instrumentation is to be per the SCAQMD Protocol for
Rule 1146.2.
3.8. Special measures – Windows or openings for viewing the flame are to be
provided to the extent that they will provide useful information and not affect
boiler operation
4. Test Gases
The following gases have been specifically formulated to cover the range of gas
compositions and calorific values of natural gases that could be delivered in the
Southern California Gas Company territory by current natural gas suppliers and future
LNG suppliers.
ƒ Baseline Gas (Gas 1) - Low Wobbe (1,302 Btu/cf), low heat content gas (1,001
Btu/cf)
ƒ Gas 2 - Lowest-Wobbe (1,269 Btu/cf), lowest-heat content gas (974 Btu/cf)
ƒ Gas 3 - Highest-Wobbe (1,436 Btu/cf), highest-heat content gas (1,152 Btu/cf)
ƒ Gas 4 - Medium-Wobbe (1,370 Btu/cf), highest-heat content gas (1,145 Btu/cf)
ƒ Gas 4A (4 component mix) - Medium-Wobbe (1,371 Btu/cf), highest-heat content
gas (1,148 Btu/cf)
ƒ Gas 5 - Medium-Wobbe (1,373 Btu/cf), high-heat content gas (1,099 Btu/cf)
ƒ Gas 5A (4 component mix) - Medium-Wobbe (1,374 Btu/cf), high-heat content
gas (1,100 Btu/cf)
ƒ Gas 6 - High Wobbe (1.412 Btu/cf), high-heat content gas (1,107 Btu/cf)
Commercial Water Boiler
16
Gas Quality and LNG Research Study
Appendix B - 2
5. Basic Operating Condition
Unless required otherwise by specific test requirements, the following are to apply:
5.1. Ambient temperature - Hold between 75°F and 85°F and measured as
specified in Sections 7.4.1.6 & 7.1.6 of the AQMD Protocol.
5.2. Gas supply pressure - 8.0 ± 0.3” w.c., measured during steady operation.
5.3. Basic firing setup - The basic firing setup is to be that combination of gas
orifice size and manifold pressure required to deliver rated input with Baseline
Gas. Manifold pressure is to be 5” w.c. ± 10% of that specified on the rating
plate. The firing rate generally will not be at rated input with gases other than
Baseline Gas.
5.4. Water flow, temperature and pressure - Adjust outlet temperature as close as
possible to 165 ± 5°F and do not make any adjustments after starting the test.
Adjust inlet temperature to obtain the required outlet temperature while following
manufacturer’s recommended installation procedures for a boiler utilized in
space heating. The inlet water should be 125 ± 5°F.
6. Testing
6.1. Startup Run - Operate boiler on Baseline Gas for one-half hour at maximum
input, as-received – i.e. with gas orifices received in the boiler and manifold
pressure at the rating plate value ± 0.2” w.c.. Fifteen minutes after starting,
check firing rate and record emissions data. Also record ambient temperature,
gas pressures, gas temperatures, gas flow, water temperatures, water supply
pressure, and stack temperature and flame temperatures.
Experiment with the boiler water temperature controls to determine what
procedures should be used to start and operate the boiler at various firing rates.
Verify proper operation of all equipment and instrumentation.
6.2. Base case at rated input - Adjust boiler to operate at the rating plate input,
maintaining manifold pressure within ±10% of that specified on the rating plate
and changing gas orifices if necessary. This establishes and defines the “basic
firing setup” referred to in Section 5.3 above. Record input rate and combustion
data and verify that the firing rate is within ± 2% of the rated input.
During the testing observe flames and note yellow tipping and flame lifting or
flashback phenomena or lack of it. Record these observations. If significant
yellow tipping was observed, inspect flue collector and vent connection area and
swab with a white cloth to determine if soot has been deposited. If soot is
present, remove it prior to continuation of testing.
Commercial Water Boiler
17
Gas Quality and LNG Research Study
Appendix B - 2
7. Steady operation testing
7.1. Steady operation tests – Baseline and substitute gases at rated input
7.1.1. Steady operation with Baseline Gas - Starting with Baseline Gas,
operate the boiler at basic operating condition. Verify that firing rate is at ± 2%
of the rated input and record combustion data (NOX, CO2 & CO) as required by
the AQMD Protocol. Do not conduct “over-fire” test.
Continue operation to establish that stack temperature changes by no more than
± 5°F in 15 minutes and that inlet and outlet water temperatures remain within
acceptable limits. Record stack temperature and that of other components
identified in Section 3.6.
During the testing observe flames and note yellow tipping and flame lifting or
flashback phenomena or lack of the same.
7.1.2. Gas changeover and steady operation with substitute gases Continue steady boiler operation with Baseline Gas and conduct a high-speed
switch to Gas 2. Record data before, during, and after changeover and observe
transient phenomena. Possible phenomena include flame color change, flame
lifting, flashback or rollout, pilot burner instability or outage, etc. (Note: The
firing rate is not to be adjusted and the boiler controls must not be allowed to
adjust firing rate in response to a water temperature change.)
Record all operating data including firing rate, stack temperature, and other
temperatures per section 7.1.1. Continue operation and record combustion data
(NOX, CO2 & CO) as required by the AQMD Protocol.
During the testing observe flames and note yellow tipping and flame lifting or
flashback phenomena or lack of the same.
With the boiler continuing to operate at steady state on the substitute gas,
conduct a high-speed switch to Baseline Gas and record observations and data
per above.
Continue testing by reestablishing steady state conditions with the Baseline Gas
and repeat the test sequence for Gas 3, 4, 5, and 6. Omit the high-speed switch
sequence to Baseline Gas between Gases 4 and 4A and between Gases 5 and
5A.
When testing has been conducted with all gases, shut down boiler and examine
emission analyzers accuracy by performing a linearity test, then check for
calibration drift by zeroing and spanning the instruments.
7.1.3. Under-fire & Over-fire Testing
7.1.3.1.
Under-fire Testing - Using Baseline Gas, adjust manifold
pressure to fire at 94% of rated input. For ten minutes record all operating
data including firing rate, stack temperature, and other temperatures per
section 7.1.1. Also, record combustion data (NOX, CO2 & CO) as required by
the AQMD Protocol.
Commercial Water Boiler
18
Gas Quality and LNG Research Study
Appendix B - 2
During the testing observe flames and note yellow tipping and flame lifting or
flashback phenomena or lack of the same.
7.1.3.2.
Over-fire Testing - Using Baseline Gas, adjust manifold pressure
to fire at 106% of rated input. For ten minutes record all operating data
including firing rate, stack temperature, and other temperatures per section
7.1.1. Also, record combustion data (NOX, CO2 & CO) as required by the
AQMD Protocol.
During the testing observe flames and note yellow tipping and flame lifting or
flashback phenomena or lack of the same.
8. Ignition Tests
8.1. Cold Ignition
Using Baseline Gas, adjust the manifold pressure to allow for a rated input of
500,000 Btu/hr ± 2%. Purge the gas delivery system of Baseline Gas with Gas 3.
Using Gas 3, ignite the boiler from a cold start for one minute. Document visual
observations of the flame, ignition delays and any other phenomena observed.
Repeat this process 2 more times, allowing the boiler to reestablish cold start
conditions in between each ignition.
Purge the gas delivery system of Gas 3 with Gas 2. Using Gas 2, ignite the
boiler from a cold start for one minute. Document visual observations of the
flame, ignition delays and any other phenomena observed. Repeat this process
2 more times, allowing the boiler to reestablish cold start conditions in between
each ignition.
8.2. Hot Ignition
Using Baseline Gas, adjust the manifold pressure to allow for a rated input of
500,000 Btu/hr ± 2%. Purge the gas delivery system of Baseline Gas with Gas
3. Using Gas 3, ignite the water heater for one minute. Document visual
observations of the flame, ignition delays and any other phenomena observed.
Repeat this process 2 more times.
Purge the gas delivery system of Gas 3 with Gas 2. Using Gas 2, ignite the
boiler for one minute. Document visual observations of the flame, ignition
delays and any other phenomena observed. Repeat this process 2 more times.
9. Special Tests
Special tests may be conducted to investigate phenomena of concern to the boiler
manufacturer. The decision of whether or not to test and the design of appropriate tests
are to be discussed with the manufacturer.
Commercial Water Boiler
19
Gas Quality and LNG Research Study
Appendix B - 2
10. Additional Testing
Conduct additional testing and/or testing with other gas blends, per the Phase II
protocol, when test results or observations indicate it is necessary.
If indicated additional testing is outside of the project scope, include appropriate
comment in the test report.
11. Calculations
CO, HC and NOX emissions (ppm, Corrected to 3% O2) are to be calculated per the
AQMD protocol for Rule 1146.2.
Rationale - Test Setup and Procedure
Firing rate:
A degree of de-rating by manufacturers is not uncommon because they must
accommodate things beyond their control such as component and process
tolerances and fuel gas property variation. Such de-rating is to be evaluated in a
“startup run” during which the boiler will be operated “as shipped” on baseline gas.
After the startup, “base case” data is to be obtained with the boiler adjusted to its
rated input. The gas orifice size and manifold pressure required to achieve that
condition with baseline gas are to be maintained during operation with the various
gas blends being evaluated.
Allowing boiler operation to “float” with gas blend makes it possible to associate
performance change with only the gas change. Existence of “as shipped” startup
data allows inference as to how factory de-rate practices might affect conclusions.
Burner and ignition operating characteristics:
Substitute gas compositions do not indicate likely problems and full-blown testing of
burner and ignition systems per the safety standards would be more extensive than
the program allows for. The testing specified in this protocol provides for observation
of deviant phenomena, but does not include investigation of pilot and valve turndown
characteristics, ignition system timing, etc.
Vent pipe choice:
ANSI Standard Z21.13 specifies that the vent pipe consist of an elbow at the vent
collar, a short horizontal section, another elbow and a vertical section, the top of
which is to be 5 ft. above the vent collar or draft relief opening, whichever is lower.
The AQMD protocol and ASHRAE Standard 103-1993 (the latter applying to boilers
with less than 300,000 Btu/hr input) require a 5 ft. vertical vent pipe.
To minimize test time the vent pipe height is specified at 5 ft. for all testing and is
allowed to be as short as 4 ft. if necessary for compatibility with laboratory ceiling
height. The height compromise departs from standards, but is not considered to
materially affect results, especially with respect to performance comparison when
gas fuel blend is changed. With respect to Standard Z21.13, a shortened vertical
stack is considered to have an effect on the order of, and probably less than, a stack
with two elbows and a horizontal section.
Commercial Water Boiler
20
Gas Quality and LNG Research Study
Appendix B - 2
Water temperature:
ANSI Standard Z21.13 specifies an inlet temperature at 80 ± 10°F and an outlet
temperature of 180 ± 2°F, unless the manufacturer states a maximum permissible
water temperature rise. In the latter case inlet water is tempered by mixing outlet
and supply water to meet the manufacturer’s specification.
The AQMD protocol specifies an inlet temperature of 70 ± 2°F and an outlet
temperature of 180 ± 2°F, unless the manufacturer states a maximum permissible
water temperature rise. In the latter case inlet water is tempered to meet the
manufacturer’s requirement.
ASHRAE Standard 103-1993 (applying to boilers with input less than 300,000 Btu/hr)
specifies a water temperature rise of 19°F to 24°F and an inlet water temperature of
120°F to 124°F.
In the belief that the differences in these specifications do not have significant effect
on safety and emission performance and in the interest of testing economy water
temperatures are specified at the same values for all testing. Outlet water
temperature is to be 180°F ± 2°F. Water temperature rise is specified at the
maximum permissible stated by the manufacturer. If a maximum rise is not stated by
the manufacturer, inlet/supply water is specified at 75 ± 5°F.
Commercial Water Boiler
21
Gas Quality and LNG Research Study
Appendix B - 2
Appendix B: Table of Averages
At Rated Input
Gases
Table of Averages
Commercial Water Boiler
Rated Input Test
August 19, 2004
Base
4
4A
Base
2
Base
3
Base
5
5A
Base
6
Base
HHV (Btu/cf)
1,001
974
1,001
1,152
1,001
1,145
1,148
1,001
1,099
1,100
1,001
1,107
1,001
Wobbe (Btu/cf)
1,302
1,269
1,302
1,436
1,302
1,370
1,371
1,302
1,373
1,374
1,302
1,412
1,302
Input Rate (Btu/hr) 478,221 464,211 475,820 526,659 473,224 510,844 501,008 474,487 504,782 502,309 474,166 514,685 474,049
Corrected SCFH
478.1
476.4
475.5
455.0
474.2
446.1
437.2
475.6
458.3
455.1
473.8
465.1
474.5
8.2
Emissions (not from certified tests)
Raw O2 (%)
8.1
8.5
8.3
6.8
8.3
7.4
7.1
8.1
7.3
7.5
8.2
7.1
Raw CO2 (%)
7.4
7.2
7.3
8.2
7.3
8.2
8.3
7.4
8.0
7.9
7.4
8.1
7.4
CO (ppm @ 3% O2)
2.3
14.8
4.3
0.5
5.4
0.1
0.2
1.1
0.1
0.1
1.4
0.3
1.9
HC (ppm @ 3% O2)
3.9
12.1
4.1
1.2
4.2
1.0
1.1
2.3
1.0
1.3
2.2
1.2
2.8
NOX (ppm @ 3% O2)
16.0
11.6
14.8
43.2
15.5
25.5
30.1
17.1
28.2
26.8
16.7
38.5
16.5
Ultimate CO2 (%)
12.1
12.2
12.1
12.3
12.1
12.6
12.6
12.1
12.3
12.3
12.1
12.2
12.1
Equivalence Ratio (Φ)
0.64
0.62
0.58
0.69
0.58
0.67
0.68
0.64
0.67
0.67
0.63
0.69
0.64
Temperatures (°F)
Ambient
78.3
78.2
78.8
78.1
78.8
79.0
79.4
80.4
79.9
79.0
79.3
79.6
78.9
Flame
1,512
1,138
1,408
1,996
1,400
1,745
1,931
1,627
1,875
1,817
1,612
1,986
1,604
Gas
77.9
77.7
77.7
77.6
78.8
79.6
79.9
80.0
79.2
79.0
79.0
78.9
78.8
Stack
494.4
484.7
492.2
508.1
492.2
496.5
502.1
491.4
497.4
494.6
497.9
502.6
499.3
Inlet Water
124.8
123.4
123.1
124.8
125.4
124.5
125.0
124.3
125.1
124.8
126.2
127.1
127.2
Outlet Water
156.1
153.6
153.1
158.0
158.7
156.3
157.6
156.0
158.1
154.2
156.5
161.0
158.8
Pressures
Supply (in. w.c.)
8.2
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.0
8.0
8.0
8.1
Manifold (in. w.c.)
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
Flow
Water Flow (gpm)
22.0
22.1
22.2
22.1
22.1
22.0
22.3
22.3
22.5
22.3
22.5
22.2
22.3
Commercial Water Boiler
22
Gas Quality and LNG Research Study
Appendix B - 2
At Various Input Rates Using Baseline Gas
Gases
Table of Averages
Commercial Water Boiler
At Various Input Rates Using Baseline Gas
August 20, 2004
500,000 Btu/hr 470,000 Btu/hr 530,000 Btu/hr 500,000 Btu/hr
± 2%
± 2%
± 2%
± 2%
HHV (Btu/cf)
1,001
1,001
1,001
1,001
Wobbe (Btu/cf)
1,302
1,302
1,302
1,302
Input Rate (Btu/hr)
478,128
459,192
510,679
485,769
Corrected SCFH
477.81
458.89
510.34
485.45
8.5
7.1
7.7
Emissions (not from certified tests)
Raw O2 (%)
7.9
Raw CO2 (%)
7.6
7.2
8.0
7.7
CO (ppm @ 3% O2)
2.8
13.4
0.5
0.7
HC (ppm @ 3% O2)
1.3
11.2
0.9
1.7
NOX (ppm @ 3% O2)
11.7
8.6
25.1
15.4
Ultimate CO2 (%)
12.2
12.2
12.2
12.2
Equivalence Ratio (Φ)
0.65
0.62
0.68
0.66
Temperatures (°F)
Ambient
76.1
78.0
75.9
77.7
Flame
1,473
1,080
1,966
1,704
Gas
78.8
80.4
78.0
77.4
Stack
493.2
479.7
505.6
501.9
Inlet Water
125.1
121.3
130.9
131.4
Outlet Water
158.2
151.3
166.7
166.0
Supply (in. w.c.)
8.1
8.2
7.9
8.1
Manifold (in. w.c.)
Flow
Water Flow (gpm)
5.1
4.9
5.5
5.2
21.7
21.9
21.0
20.9
Pressures
Commercial Water Boiler
23
Gas Quality and LNG Research Study
Appendix B - 2
Appendix C: Test Gases
Gas Analysis
Sample Date
COMPONENTS
C6 + 57/28/14
NITROGEN
METHANE
CARBON DIOXIDE
ETHANE
PROPANE
i-BUTANE
n-BUTANE
NEOPENTANE
i-PENTANE
n-PENTANE
OXYGEN
TOTAL
Compressibility Factor
HHV (Btu/real cubic foot)
LHV (Btu/real cubic foot)
Specific Gravity
WOBBE Index
Baseline
8/4/04
MolPct
0.0200
1.9100
94.3900
1.2400
1.6600
0.3100
0.0600
0.0500
0.0000
0.0200
0.0100
0.3300
100.000
2
8/5/04
MolPct
0.0307
1.0866
95.8713
2.9973
0.0000
0.0141
0.0000
0.0000
0.0000
0.0000
0.0000
0.0000
100.000
3
7/27/04
MolPct
0.0297
0.0609
86.7978
0.0000
9.3416
2.7663
1.0037
0.0000
0.0000
0.0000
0.0000
0.0000
100.000
4
8/5/04
MolPct
0.1858
1.0608
84.9713
3.0005
4.7846
2.4015
1.1936
1.2074
0.0000
0.5944
0.6001
0.0000
100.000
4A
7/27/04
MolPct
0.0406
1.0782
84.3951
3.0516
0.0220
11.3998
0.0094
0.0033
0.0000
0.0000
0.0000
0.0000
100.000
5
8/18/04
MolPct
0.0737
0.8003
88.8139
1.4074
5.2987
2.6048
0.0022
0.8424
0.0000
0.1567
0.0000
0.0000
100.000
5A
7/19/04
MolPct
0.0435
0.7777
90.8094
1.4130
0.0230
6.9175
0.0113
0.0046
0.0000
0.0000
0.0000
0.0000
100.000
6
8/7/04
MolPct
0.0000
0.0000
91.6800
0.0000
5.5300
1.7500
0.5200
0.5200
0.0000
0.0000
0.0000
0.0000
100.000
0.9980
1000.66
901.62
0.5906
1302.13
0.9980
974.40
877.27
0.5895
1269.12
0.9972
1151.62
1041.31
0.6434
1435.73
0.9969
1145.13
1035.92
0.6989
1369.72
0.9969
1148.33
1039.51
0.7018
1370.73
0.9974
1099.38
993.10
0.6407
1373.49
0.9974
1099.82
993.61
0.6410
1373.72
0.9975
1107.06
999.82
0.6143
1412.47
Commercial Water Boiler
24
Gas Quality and LNG Research Study
Appendix B - 2
Appendix D: Zero, Span and Linearity Tables
August 19, 2004 (At Rated Input)
Linearity
Span
Zero
Zero, Span & Linearity Data
Commercial Water Boiler
August 19, 2004
Analyzer Emission Ranges
Zero Calibration Gas (Low-Range Values)
Allowable Zero Drift (Less Than ± 3% of Range)
Zero Calibration - 10:08:06 AM
Zero Drift Check - 3:05:04 PM
Total Drift Over Test Period
Was the Zero Drift Within Allowable Deviation?
Span Calibration Gas (High-Range Values)
Allowable Span Drift (Less Than ± 3% of Range)
Span Calibration - 10:18:36 AM
Span Drift Check - 2:55:36 PM
Total Drift Over Test Period
Was the Span Drift Within Allowable Deviation?
Linearity Calibration Gas (Mid-Range Values)
Allowable Linearity Drift (Less Than ±1% of Range)
Linearity Check - 10:23:57 AM (CO: 11:05:34 AM)
Difference From Mid-Range Values
Was the Linearity Within Allowable Deviation?
Linearity Check - 3:00:02 PM
Difference From Mid-Range Values
Was the Linearity Within Allowable Deviation?
Commercial Water Boiler
25
O2 (%)
CO2 (%)
0 - 25
0.00
0.75
0.23
0.20
0.03
Yes
20.90
0.75
20.95
20.93
0.02
Yes
9.03
0.25
9.22
0.19
Yes
9.05
0.02
Yes
0 - 20
0.00
0.60
0.04
0.08
0.04
Yes
12.20
0.60
12.20
12.25
0.05
Yes
8.00
0.20
7.94
0.06
Yes
7.96
0.04
Yes
CO
(ppm)
0 - 200
0.00
6.00
0.46
-2.06
2.52
Yes
182.40
6.00
181.86
182.13
0.27
Yes
91.20
2.00
90.30
0.90
Yes
89.68
1.52
Yes
HC
(ppm)
0 - 1000
0.00
30.00
0.44
0.27
0.17
Yes
434.00
30.00
434.77
438.25
3.48
Yes
434.00
10.00
435.64
1.64
Yes
438.75
4.75
Yes
NOx
(ppm)
0 - 100
0.00
3.00
0.05
0.85
0.80
Yes
84.37
3.00
84.66
84.39
0.27
Yes
42.86
1.00
41.53
1.33
No
42.07
0.79
Yes
Gas Quality and LNG Research Study
Appendix B - 2
August 20, 2004 (Various Input Rated - Baseline Gas Only)
Linearity
Span
Zero
Zero, Span & Linearity Table
Commercial Water Boiler
August 20, 2004
Analyzer Emission Ranges
Zero Calibration Gas (Low-Range Values)
Allowable Zero Drift (Less Than ± 3% of Range)
Zero Calibration - 8:54:33 AM
Zero Check - 11:01:35 AM
Total Drift Over Test Period
Was the Zero Drift Within Allowable Deviation?
Span Calibration Gas (High-Range Values)
Allowable Span Drift (Less Than ± 3% of Range)
Span Calibration - 8:58:59 AM
Span Check - 11:05:13 AM
Total Drift Over Test Period
Was the Span Drift Within Allowable Deviation?
Linearity Calibration Gas (Mid-Range Values)
Allowable Linearity Drift (Less Than ±1% of Range)
Linearity Check - 9:06:01 AM
Difference From Mid-Range Values
Was the Linearity Within Allowable Deviation?
Linearity Check - 11:08:31 AM
Difference From Mid-Range Values
Was the Linearity Within Allowable Deviation?
Commercial Water Boiler
26
O2 (%)
CO2 (%)
0 - 25
0.00
0.75
0.25
0.19
0.06
Yes
20.90
0.75
20.82
20.81
0.01
Yes
9.03
0.25
9.15
0.12
Yes
9.12
0.09
Yes
0 - 20
0.00
0.60
0.02
0.15
0.13
Yes
12.20
0.60
12.20
12.46
0.26
Yes
8.00
0.20
7.94
0.06
Yes
8.11
0.11
Yes
CO
(ppm)
0 - 200
0.00
6.00
0.27
0.38
0.11
Yes
182.50
6.00
183.01
184.14
1.13
Yes
91.25
2.00
91.79
0.54
Yes
90.66
0.59
Yes
HC
(ppm)
0 - 1000
0.00
30.00
-0.08
0.17
0.25
Yes
434.00
30.00
436.51
446.32
9.81
Yes
434.00
10.00
436.13
2.13
Yes
446.61
12.61
No
NOx
(ppm)
0 - 100
0.00
3.00
-0.06
1.80
1.86
Yes
84.37
3.00
86.50
86.54
0.04
Yes
42.86
1.00
43.06
0.20
Yes
43.53
0.67
Yes
Gas Quality and LNG Research Study
Appendix B - 2
Appendix E: Calculations
Emission Concentrations
Corrected to O2 Standard (3% O2)
⎡ 20.9 − 3 ⎤
CO, HC & NO x Concentrat ions (corrected to 3% O 2 ) = Raw Concentrat ions (ppm) × ⎢
⎥
⎣ 20.9 − % O 2 ⎦
Where
Raw Concentration = Measured CO, HC & NOx concentrations, by volume (ppm)
% O2 = Measured O2 Concentration
Ultimate CO2
⎤
⎡
20.9
Ult. CO 2 = Raw CO2 × ⎢
⎥
⎣ 20.9 − Raw O 2 ⎦
Where
Ult. CO2 = Ultimate CO2 (%)
Raw CO2 = Measured CO2 Concentration (%)
Raw O2 = Measured O2 Concentration (%)
Commercial Water Boiler
27
Gas Quality and LNG Research Study
Appendix B - 2
% Excess Air
Constituent
Balanced Chemical Composition
Theo. Air
Theo. Flue Gas
Methane (CH4)
CH4 + 2O2 + 2(3.78)N2 ==> 1CO2 + 2H2O + 2(3.78)N2
9.56
8.56
Ethane (C2H6)
C2H6 + 3.5O2 + 3.5(3.78)N2 ==> 2CO2 + 3H2O + 3.5(3.78)N2
16.73
15.23
Propane (C3H8)
C3H8 + 5O2 + 5(3.78)N2 ==> 3CO2 + 4H2O + 5(3.78)N2
23.90
21.90
i-Butane (C4H10)
C4H10 + 6.5O2 + 6.5(3.78)N2 ==> 4CO2 + 5H2O + 6.5(3.78)N2
31.07
28.57
n-Butane (C4H10)
C4H10 + 6.5O2 + 6.5(3.78)N2 ==> 4CO2 + 5H2O + 6.5(3.78)N2
31.07
28.57
i-Pentane (C5H12)
C5H12 + 8O2 + 8(3.78)N2 ==> 5CO2 + 6H2O + 8(3.78)N2
38.24
35.24
n-Pentane (C5H12)
C5H12 + 8O2 + 8(3.78)N2 ==> 5CO2 + 6H2O + 8(3.78)N2
38.24
35.24
Hexanes (C6H14)
C6H14 + 9.5O2 + 9.5(3.78)N2 ==> 6CO2 + 7H2O + 9.5(3.78)N2
45.41
41.91
To determine the % Excess Air, the theoretical air and theoretical flue gas values for
each gas tested must be calculated. The table above lists the constituents found in
natural gas, the balanced chemical equations for each constituent and their respective
theoretical air and theoretical flue gas values (expressed in moles).
The theoretical air value for each constituent is the sum of moles for both O2 and N2 on
the reactants side of the balanced chemical equation (ex: For Methane, 2 moles of O2
plus 7.56 moles of N2 = 9.56 moles of Theoretical Air). The theoretical flue value for
each constituent is the sum of moles for both CO2 and N2 on the product side of the
balanced chemical equation (ex: For Methane, 1 mole of CO2 plus 7.56 moles of N2 =
8.56 moles of Theoretical Flue Gas).
Once the test gases have been analyzed (via gas chromatography), the % composition
of each gas is used to determine the theoretical air and theoretical flue gas values for
each gas tested. Thus,
Theoretica l Air = ∑ C1P + C2P + ... + CnP
Theoretica l Flue = ∑ D1P + D2P + ... + DnP
Where C is the theoretical air value for each constituent, D is the theoretical flue gas
value for each constituent and P is the percent composition for each constituent
(expressed as a decimal, not a percentage). Therefore, the % Excess Air is calculated
as follows:
⎡
⎤
Ult.CO2 − Raw CO2
% Excess Air = ⎢Theo. Flue Value ×
⎥ × 100
Theo. Air Value × Raw CO2 ⎦
⎣
Air/Fuel Ratio
Air/Fuel Ratio = Theo. Air Value +
Commercial Water Boiler
28
Theo. Air Value × % Excess Air
100
Gas Quality and LNG Research Study
Appendix B - 2
Equivalence Ratio (φ)
Equivalence Ratio (φ ) =
100
100 + % Excess Air
Gas Meter Correction
To determine the corrected SCFH for each appliance tested, the accuracy of the 8C gas
meter was checked to determine the correction factor for each meter (Table shown
below).
Given the range of the input rate, the slope (m) of the line was determined setting
y = average correction percentage and x = cubic feet per hour (cfh). Next, the
y-intercept/correction factor (b) was determined using the y-intercept equation
(y = mx + b). Once the correction factor (b) is known, the y-intercept equation was used
again to calculate the corrected SCFH; this time x = uncorrected SCFH value.
Model Number: 8C
Date: September 22, 2004
Meter Number: 11335393
TESTS WERE CONDUCTED USING
20 CU. FT. BELL PROVER #3226
CFH
OK Counts
Proofs (%)
800
961
+ 0.10
700
961
+ 0.20
600
960
+ 0.10
500
958
- 0.30
400
958
- 0.30
200
955
- 0.10
100
955
- 0.10
Barometric Pressure Correction
Using the Standard Atmosphere Data for Altitudes to 60,000 ft Table (Table 3, ASHRAE
1989 Fundamentals Handbook, pg. 6.12), the barometric pressure at the test facility
elevation was determined by linear interpolation. This value was subtracted from the
barometric pressure value at sea level (29.921 in. Hg or 14.696 psia) to obtain the
correction value. The correction value was subtracted from the barometric pressure
reading specific to the hour and day of testing and then it was converted to absolute
pressure (psia) using the following equation:
⎡ 14.696 psia ⎤
Baro. Press ( in.Hg) × ⎢
⎥ = Baro. Press(psia )
⎣ 29.921 in. Hg ⎦
Commercial Water Boiler
29
Gas Quality and LNG Research Study
Appendix B - 2
SCFH (Uncorrected)
⎤
⎡P
(psig) + PBarometric (psia )⎤ ⎡
Tstandard
SCFH = ACFH × ⎢ Fuel
⎥
⎥×⎢
ο
Pstandard
⎣
⎦ ⎢⎣ TFuel ( F) + 459.67 ⎦⎥
Where
SCFH = Standard Cubic Feet per Hour (Uncorrected)
ACFH = Actual Cubic Feet per Hour
PFuel = Gas Supply Pressure (psig)
PBarometric = Barometric Pressure (psia)
Pstandard = Standard Pressure (14.696 psia)
Tstandard = Standard Temperature (519.67 R @ 1 atm)
TFuel = Fuel Temperature (°F)
SCFH (Corrected)
Corrected SCFH = SCFH + Meter Correction Factor
Input Rate (Btu/cf)
Input Rate = Corrected SCFH × HHV
Where
HHV = Higher Heating Value (Btu/cf)
Wobbe Number (Btu/cf)
W0 =
HHV
Where
W0 = Wobbe Number (Btu/cf)
HHV = Higher Heating Value (Btu/cf)
G = Specific gravity of gas sample
Commercial Water Boiler
30
G
Gas Quality and LNG Research Study
Appendix B - 2
Appendix F: Test Equipment
Emissions Analyzers
Analyzer
Manufacturer
Model
Type
Accuracy
NO/NOx
Thermo Environmental
Instruments Inc.
10AR
Chemiluminescent
± 1% of full scale
CO
Thermo Environmental
Instruments Inc.
48
Nondispersive infrared
(NDIR) gas analyzer
± 1% of full scale
CO2
Fuji
ARH
Nondispersive infrared
(NDIR) gas analyzer
± 1% of full scale
HC
California Analytical
Instruments, Inc.
300 HFID
Flame ionization detector
(FID)
± 1% of full scale
O2
Teledyne
326RA
Electrochemical cell
± 1% of full scale
Calibration Gases
Gas
Manufacturer
Type
Accuracy
NO/NOx
Scott Specialty Gases
Certified Master Class – 18.95 ppm
±2%
CO
Scott Specialty Gases
Certified Master Class – 79.3 ppm
±2%
CO2
Scott Specialty Gases
Certified Master Class – 12.1 %
±2%
HC
Scott Specialty Gases
Certified Master Class – 0.5 ppm
±2%
O2
Scott Specialty Gases
Certified Master Class – 9.1 %
±2%
Zero
Scott Specialty Gases
Certified Master Class – 0 %
±2%
Test Equipment
Type
Manufacturer
Model
Accuracy
Gas Chromatograph
Agilent
6890
± 0.5 BTU/scf
Type J Thermocouple
Omega Engineering Co.
JMQSS
2.2°C or 0.75%
Type K Thermocouple
Omega Engineering Co.
KMQSS
2.2°C or 0.75%
Type R Thermocouple
Omega Engineering Co.
RMQSS
2.2°C or 0.75%
Type T Thermocouple
Omega Engineering Co.
TMQSS
2.2°C or 0.75%
Drytest Gas Meter
800 cf/h max
Roots Meter
8C175
N/A
Gas Meter Pulser
2 pulses per 1/10 cf
Rio Tronics
4008468
N/A
Gas Pressure Regulator
Fisher
299H
± 1.0 %
Differential Pressure
Transmitter
Dwyer
607-4
±0.25 -0.50%
Pressure Transducer
Omega
PX205-100GI
±0.25% of full
scale
Data Logger
Logic Beach
Hyper Logger
N/A
Commercial Water Boiler
31
Gas Quality and LNG Research Study
Appendix B - 2
Appendix G: Test Set-Up/Schematic
Equipment utilized for testing adheres to industry standards for testing laboratories that
certify such equipment. The test rig is transportable and includes a data logger,
emissions cart, gas meter, thermocouples and pressure transducers; plus, a gas
regulation system that can take natural gas from 3,000 PSIG and deliver up to 2,000
CFH at low pressure (~8” w.c.). The test rig is illustrated below.
TEST RIG
LAPTOP
DATA LOGGER
THERMOCOUPLES
PRESSURE
P
TEMPERATURE
T
GAS METER
W ITH PULSER
END-USER
EQUIPMENT
T
REGULATOR
P
BALL
VALVE
EMISSION
ANALYZER
O2, CO2
CO, NOx
HEAT EXCHANGER
HC
DATA
LOGGER
BALL VALVE
REGULATOR
BALL VALVE
COMPUTER
GAS
CYLINDERS
Commercial Water Boiler
BASELINE
GAS
32